/*
 * Copyright (c) 2020 rxi
 *
 * Permission is hereby granted, free of charge, to any person obtaining a copy
 * of this software and associated documentation files (the "Software"), to
 * deal in the Software without restriction, including without limitation the
 * rights to use, copy, modify, merge, publish, distribute, sublicense, and/or
 * sell copies of the Software, and to permit persons to whom the Software is
 * furnished to do so, subject to the following conditions:
 *
 * The above copyright notice and this permission notice shall be included in
 * all copies or substantial portions of the Software.
 *
 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
 * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
 * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS
 * IN THE SOFTWARE.
 */

#include "clog.h"

#define MAX_CALLBACKS 32

typedef struct {
  clogLogFn fn;
  void *udata;
  int level;
} Callback;

static struct {
  void *udata;
  clogLockFn lock;
  int level;
  bool quiet;
  Callback callbacks[MAX_CALLBACKS];
} CLOG;

static const char *level_strings[] = {"TRACE", "DEBUG", "INFO",
                                      "WARN",  "ERROR", "FATAL"};

static const char *level_colors[] = {"\x1b[94m", "\x1b[36m", "\x1b[32m",
                                     "\x1b[33m", "\x1b[31m", "\x1b[35m"};

static void stdout_callback(ClogEvent *ev) {
  char buf[16];
  buf[strftime(buf, sizeof(buf), "%H:%M:%S", ev->time)] = '\0';
  fprintf((FILE *)ev->udata, "%s %s%-5s\x1b[0m \x1b[90m%s:%d:\x1b[0m ", buf,
          level_colors[ev->level], level_strings[ev->level], ev->file,
          ev->line);
  vfprintf((FILE *)ev->udata, ev->fmt, ev->ap);
  fprintf((FILE *)ev->udata, "\n");
  fflush((FILE *)ev->udata);
}

static void file_callback(ClogEvent *ev) {
  char buf[64];
  buf[strftime(buf, sizeof(buf), "%Y-%m-%d %H:%M:%S", ev->time)] = '\0';
  fprintf((FILE *)ev->udata, "%s %-5s %s:%d: ", buf, level_strings[ev->level],
          ev->file, ev->line);
  vfprintf((FILE *)ev->udata, ev->fmt, ev->ap);
  fprintf((FILE *)ev->udata, "\n");
  fflush((FILE *)ev->udata);
}

static void lock(void) {
  if (CLOG.lock) {
    CLOG.lock(true, CLOG.udata);
  }
}

static void unlock(void) {
  if (CLOG.lock) {
    CLOG.lock(false, CLOG.udata);
  }
}

void clogSetLock(clogLockFn fn, void *udata) {
  CLOG.lock = fn;
  CLOG.udata = udata;
}

void clogSetLevel(int level) { CLOG.level = level; }

void clogSetQuiet(bool enable) { CLOG.quiet = enable; }

int clogAddCallback(clogLogFn fn, void *udata, int level) {
  for (int i = 0; i < MAX_CALLBACKS; i++) {
    if (!CLOG.callbacks[i].fn) {
      CLOG.callbacks[i].fn = fn;
      CLOG.callbacks[i].udata = udata;
      CLOG.callbacks[i].level = level;
      return 0;
    }
  }
  return -1;
}

int clogAddFp(FILE *fp, int level) {
  return clogAddCallback(file_callback, fp, level);
}

static void init_event(ClogEvent *ev, void *udata) {
  time_t t = time(NULL);
  localtime_s(ev->time, &t);
  ev->udata = udata;
}

void clog(int level, const char *file, int line, const char *fmt, ...) {
  ClogEvent ev{0};
  ev.level = level;
  ev.file = file;
  ev.line = line;
  ev.fmt = fmt;
  ev.time = new tm;

  lock();

  if (!CLOG.quiet && level >= CLOG.level) {
    init_event(&ev, stderr);
    va_start(ev.ap, fmt);
    stdout_callback(&ev);
    va_end(ev.ap);
  }

  for (int i = 0; i < MAX_CALLBACKS && CLOG.callbacks[i].fn; i++) {
    Callback *cb = &CLOG.callbacks[i];
    if (level >= cb->level) {
      init_event(&ev, cb->udata);
      va_start(ev.ap, fmt);
      cb->fn(&ev);
      va_end(ev.ap);
    }
  }
  unlock();
  delete ev.time;
}
